Synthesis of graphene films by rapid heating and quenching at ambient pressures and their electrochemical characterization.

We study the process of graphene growth on Cu and Ni substrates subjected to rapid heating (approximately 8 °C/s) and cooling cycles (approximately 10 °C/s) in a modified atmospheric pressure chemical vapor deposition furnace. Electron microscopy followed by Raman spectroscopy demonstrated successful synthesis of large-area few-layer graphene (FLG) films on both Cu and Ni substrates. The overall synthesis time was less than 30 min. Further, the as-synthesized films were directly utilized as anode material and their electrochemical behavior was studied in a lithium half-cell configuration. FLG on Cu (Cu-G) showed reduced lithium-intercalation capacity when compared with SLG, BLG and Bare-Cu suggesting its substrate protective nature (barrier to Li-ions). Although graphene films on Ni (Ni-G) showed better Li-cycling ability similar to that of other carbons suggesting that the presence of graphene edge planes (typical of Ni-G) is important in effective uptake and release of Li-ions in these materials.